Subsoil plows are referred to by those in the trade as blade plows, sweep plows and sometimes as stubble mulch plows. The same basic function of these plows is to break up or loosen the subsoil without significantly disturbing the soil's surface so that fertilizers and weed control substances can be introduced into the subsoil. By disturbing the soil's surface as little as possible, erosion and soil water losses due to evaporation can be minimized.
A conventional subsoil plow has a V-shaped plow blade which is sometimes referred to as a frog. The plow blade is typically mounted to and suspended from a shank sometimes referred to as a standard. The shank, in turn, is suspended from and secured to a wheeled support frame which, in turn, is hitched to and pulled by a tractor or like powered vehicle. A subsoil plow is also typically used in conjunction with a large coulter blade which is also suspended from the support frame. The coulter blade is aligned with and located in front of the blade's point which is the point in the V of the V-shaped blade. The coulter blade serves to loosen soil for the subsoil plow's shank so that the plow can be pulled easier through the soil, i.e. with less resistance.
When plowing with a conventional subsoil plow, the V-shaped blade is located below the soil's surface to loosen the soil so that, as previously mentioned, fertilizer and weed control substances can be introduced into the soil. The V-shaped blade is generally located a selected distance below the soil surface and generally is oriented with respect to the soil surface so that a geometric plane passing through the blade's V-shape is essentially parallel to the soil's surface. The shank has a top end and bottom end. The bottom end is attached to the V-shaped blade at a point behind the blade's point. The shank extends generally upwardly from the blade in an upright or generally vertical position for approximately two and one half feet and is secured to the support frame at its top end.
While subsoil plows have been in existence for many years, efforts are continually being made to improve their performance, reliability and reduce fuel consumption of the vehicles employed to pull the plows.
The Sunflower Manufacturing Company, Inc. of Beloit, Kan. notes in its Series D 3000 Flex-King blade plows brochure that its plow's standard or shank narrows to a streamlined, slim shape wherever soil is to be contacted to keep soil disturbance at a minimum. The slim shape of the shank also makes it easier for a tractor to pull the plow.
The Krause Plow Corp. of Hutchinson, Kans., recently pointed out in its 3700 series "Flex-Wing" sweep plow brochure, Form No. 3700SP, that tractor fuel consumption can be reduced by preventing dirt from building up on the bottom portion of the shank which is located against the plow's blade. Krause notes that dirt build up in this area increases fuel consumption since it increases draft or friction between the shank and the soil during plowing. Krause states that dirt build up in this area can be eliminated by mounting the plow's shank to the blade at a location very close to the blade point. Krause states that an ordinary plow allows dirt to build up in this area since the shank is mounted too far back on the blade which creates a space between the blade point and the shank which collects dirt, particularly moist dirt.
While mounting of the shank at a location close to the blade point undoubtedly minimizes dirt build up in this area as noted by Krause, it would be desirable to completely eliminate dirt build up in this area. It would also be desirable if it were somehow possible to retrofit existing conventional subsoil plows to eliminate or at least minimize the build up of dirt in this area of the plow's shank.